It is planned to further improve the gas chromatographic-mass spectrometric peptide sequencing technique developed during the past grant periods while it is applied to the structure determination of small proteins. The improvements aim at increase in sensitivity and increased gas chromatographic resolution, the latter by the use of capillary columns. Work has already begun on the sequencing of a protein of about 230 amino acids and it is anticipated that most if not all of its structure will be determined in the coming year.